Collaborative based caching

ABSTRACT

A computer system for collaborative caching of files during a collaboration session includes program instructions for receiving a request from a first electronic device for a first file. The program instructions determine whether the first file is stored in one or more caches, wherein the one or more caches are associated with one or more electronic devices. Responsive to determining the first file is stored in a cache of a second electronic device, the program instructions determine whether the first file stored in the cache of the second electronic device meets a set of guidelines. Responsive to determining the first file stored in the cache of the second electronic device meets the set of guidelines, the program instructions send the first file from the cache of the second electronic device via an internal network to the first electronic device.

BACKGROUND

The present invention relates generally to collaboration sessions andmore particularly to collaborative caching of files during acollaboration session.

Typical collaborative sessions, such as teleconferences, includemultiple participants, where each participant may be located in variouslocations. The collaborative sessions can include the multipleparticipants utilizing links to dashboards, wiki pages, and filedocuments. In instances where screen sharing is not utilized by aparticipant leading a collaboration session, the leading participantmoves the agenda of the collaboration session and the progression ispredictable since the leading participant is first to progress. As aresult, the other participants follow the progression of the leadingparticipant and select links or attempt to access the files the leadingparticipant has already selected. As the other participants select linksor attempt to access the files, requests from the other participants aresent to the server and the server responds to each of the requests.

SUMMARY

Embodiments of the present invention includes a method, computer programproduct and computer system for collaborative caching of files during acollaboration session. A computer system includes program instructionsto receive a request from a first electronic device for a first fileduring a collaboration session between at least a first participantassociated with the first electronic device and a second participantassociated with a second electronic device; program instructions todetermine whether the first file is stored in one or more caches,wherein the one or more caches are associated with one or moreelectronic devices in the collaboration session; program instructionsto, responsive to determining the first file is stored in a first cacheof the second electronic device, determine whether the first file storedin the first cache of the second electronic device meets a set ofguidelines; program instructions to, responsive to determining the firstfile stored in the first cache of the second electronic device meets theset of guidelines, wherein the set of guidelines includes at least aduration of time the first file has been stored in the cache of thesecond electronic device and a type of device for the second electronicdevice, send the first file from the first cache of the secondelectronic device via an internal network to the first electronicdevice; program instructions to receive a request for a second file fromthe first electronic device; program instructions to determine whetherthe second file is stored in the one or more caches; programinstructions to, responsive to determining the second file is not storedin the one or more caches, query an external electronic device throughan external network for the second file; and program instructions to,responsive to receiving the second file from the electronic externaldevice, store a first portion of the second file in a second cache ofthe first electronic device and storing, by one or more processors, asecond portion of the second file in the first cache of the secondelectronic device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram illustrating a distributed dataprocessing environment, in an embodiment in accordance with the presentinvention.

FIG. 2 is a flowchart depicting one embodiment of a collaborationprogram for collaborative caching of files during a collaborationsession, in accordance with the present invention.

FIG. 3 is a block diagram of components of a computer system, such asthe computer server of FIG. 1, in an embodiment in accordance with thepresent invention.

DETAILED DESCRIPTION

Embodiments in accordance with the present invention allow forparticipants of a collaboration session to share resources over aninternal network, where resources can include video or document files.The sharing of these resources can occur during a collaboration sessionbetween the participants of the collaboration session. Embodiments inaccordance with the present invention can manage the shared resources toprevent duplication and to anticipate resource selection by theparticipants of the collaboration session. For example, if a hostparticipant of a collaboration session selects resources to view,embodiments in accordance with the present invention can determine thatthe other participants are to select the same resources selected by thehost participant. Storing the resource from the initial request by thehost participant in a local cache enables the local cache to satisfysubsequent requests for the resource through an internal network ratherthan through an external network.

Example embodiments in accordance with the present invention will now bedescribed in detail with reference to the drawing figures. FIG. 1 is afunctional block diagram illustrating a distributed data processingenvironment. The distributed data processing environment includes servercomputer 102, client device 104A, client device 104B, and client device104C interconnected over internal network 106. The distributed dataprocessing environment also includes server computer 102 and servercomputer 108 interconnected over external network 110.

Server computer 102 may be a desktop computer, a laptop computer, atablet computer, a specialized computer server, a smartphone, or anyother computer system known in the art. In certain embodiments, servercomputer 102 represents a computer system utilizing clustered computersand components that act as a single pool of seamless resources whenaccessed through internal network 106, as is common in data centers andwith cloud computing applications. In general, server computer 102 isrepresentative of any programmable electronic device or combination ofprogrammable electronic devices capable of executing machine readableprogram instructions and communicating with other computer devices via anetwork. Collaboration cache 114 in server computer 102 represent atemporary storage medium during a collaboration session, where filesstored in collaboration cache 114 are accessible by client device 104A,104B, and 104C via internal network 106.

Collaboration program 112 located on server computer 102 has the abilityto manage collaborative caches during a collaboration session.Collaboration program 112 can receive a request for a file from aparticipant of a collaboration session and determine if the file islocated in one or more of collaboration cache 114, 116A, 116B, and 116C.Responsive to collaboration program 112 determining the file exists inone or more collaboration cache 114, 116A, 116B, and 116C, collaborationprogram 112 determines if the stored file meets guidelines prior tosending the file to the requesting participant. Alternatively,responsive to collaboration program 112 determining the file does notexist in one or more collaboration cache 114, 116A, 116B, and 116C,collaboration program 112 queries server computer 108 for the filestored in content 120. Collaboration program 112 can receive the filefrom server computer 108, send the file to the requesting participant,and store the file in one or more collaboration caches 114, 116A, 116B,and 116C.

Client device 104A, 104B, and 104C may be a desktop computer, a laptopcomputer, a tablet computer, a specialized computer server, a smartphone, or any programmable electronic device capable of communicatingwith server computer 102 via internal network 106, as well as, withserver computer 108 via external network 110. In general, client device104A, 104B, and 104C represent any programmable electronic device orcombination of programmable electronic devices capable of executingmachine readable program instructions and communicating with othercomputing devices via a network, such as internal network 106 andexternal network 110. Client device 104A, 104B, and 106C includecollaboration cache 116A, 116B, and 116C, respectively. Collaborationcache 116A, 116B, and 116C represent temporary storage mediums during acollaboration session, where files stored in collaboration cache 116A,116B, and 116C are accessible by participants of the collaborationsession via internal network 106. Collaboration program 112 has theability to store a file in portions across collaboration cache 114,116A, 116B, and 116C. For example, collaboration program 112 can store afirst portion of a file in collaboration cache 114 and a second portionof the file in collaboration cache 116B.

Server computer 108 may be a desktop computer, a laptop computer, atablet computer, a specialized computer server, a smartphone, or anyother computer system known in the art. In certain embodiments, servercomputer 108 represents a computer system utilizing clustered computersand components that act as a single pool of seamless resources whenaccessed through external network 110, as is common in data centers andwith cloud computing applications. In general, server computer 108 isrepresentative of any programmable electronic device or combination ofprogrammable electronic devices capable of executing machine readableprogram instructions and communicating with other computer devices via anetwork. Server computer 108 represents an external device collaborationprogram 112 queries for the file requested by a participant of acollaboration session in the event the file is not stored in one or moreof cache 114, 116A, 116B, and 116C.

Storage 118 in server computer 108 stores content 120, where content 120represents the file being requested by a participant of a collaborationsession. Similar to server computer 108, storage 118 is accessiblethrough external network 110. Storage 118 can experience latencies whenreceiving a large quantity of requests for the same file. As a result,collaboration program 112 manages the requests for the file by queryingstorage 118 for the file to satisfy the initial request, storing thefile in one or more cache 114, 116A, 116B, and 116C, and handling thesubsequent requests for the file by querying one or more caches 114,116A, 116B, and 116C via internal network 106. In another embodiment,client device 104A, 104B, and 104C can communicate directly with servercomputer 108 via another network not illustrated in FIG. 1.

In general, internal network 106 can be any combination of connectionsand protocols that will support communications among server computer 102and client device 104A, 104B, and 104C. Internal network 106 caninclude, for example, a local area network (LAN), a wide area network(WAN), such as the internet, a cellular network, or any combination ofthe preceding, and can further include wired, wireless, and/or fiberoptic connections. In one embodiment, collaboration program 112 can be aweb service accessible via internal network 106 to a user of clientdevice 104A, 104B, and 104C. In another embodiment, collaborationprogram 112 may be operated directly by a user of server computer 102.External network 110 can be any combination of connections and protocolsthat will support communications among server computer 102 and servercomputer 108. External network 110 can include, for example, a localarea network (LAN), a wide area network (WAN), such as the internet, acellular network, or any combination of the preceding, and can furtherinclude wired, wireless, and/or fiber optic connections.

FIG. 2 is a flowchart depicting one embodiment of a collaborationprogram for collaborative caching of files during a collaborationsession, in accordance with the present invention. As depicted, themethod includes identifying (202) participants of a collaborationsession, receiving (204) a request for a file, determining (206) whetherthe file is stored in cache, querying (208) an external device for therequested file, receiving (210) the requested file, sending (212) thereceived file to the requesting participant, storing (214) the receivedfile in cache, determining (216) whether the file stored in cache meetsguidelines, and sending (218) the file to the request participant. Inone embodiment, the method is conducted by collaboration program 112.

The method may commence by identifying (202) participants of acollaboration session. In this embodiment, a collaboration session inform of a teleconference is occurring, where participants of thecollaboration session are connected to a local network. Thecollaboration session is initialized when a host participant joins thecollaboration session (i.e., connects to the teleconference) and thecollaboration session terminates when the host participant leaves thecollaboration sessions (i.e., disconnects from the teleconference).Collaboration program 112 can identify participants through individualcalendars associated with each participant or unique call-in accesscodes for the teleconference. In one example, the host participant hasthe ability to utilize collaboration program 112 to query an externaldevice (i.e., server computer 108) for one or more files which are to beutilized during the meeting when the host participant joins theteleconference. As a result, any known files needed for the meeting arestored in a local centralized storage (i.e., collaboration cache 114,116A, 116B, and cache 116C) and accessible through internal network 106by client device 104A, 104B, and 104C.

Through the local network, a participant has access to a centralizedcache on a local server (such as server computer 102) and acollaboration cache on each client device taking part in thecollaboration session. In one example, a participant may be linked to aspecific collaboration session based on whether or not the participantreceived and approved an invitation to take part in the collaborationsession. In this embodiment, a particular participant has access toanother participant's collaboration cache only during the duration thatthe data is stored in the collaboration cache. In another embodiment, aparticular participant has access to another participant's collaborationcache if the select participant previously received approval to accessthe other participant's cache.

The method may continue by receiving (204) a request for a file from aparticipant. In this embodiment, collaboration program 112 receives arequest for a video file from a participant taking part in theparticipation sessions. Collaboration program 112 can log the requestfor the video file and determine if the video file has been requested byanother participant of the collaboration session. Additionally,collaboration program 112 can track the progress of each request for thevideo file by other participants. As a result, collaboration program 112can determine whether the video file is in the process of beingdownloaded by another participant and whether the video file has alreadybeen downloaded by another participant. Collaboration program 112maintains the log of requests and tracks the progress of each requestuntil the collaboration session is terminated when the host participantleaves the collaboration session. In another embodiment, collaborationprogram 112 maintains the log of request and tracks the progress of eachrequest until the final participant leaves the collaboration session.

The method may continue by determining (206) whether the file is storedin cache. In this embodiment, collaboration program 112 determines ifthe file is stored in a collaboration cache located on a local server(such as server computer 102), where the local server is accessible byparticipants of the collaboration session. Additionally, collaborationprogram 112 determines if the file is stored in collaboration caches ofclient devices associated with the participants of the collaborationsessions. Due to collaboration program 112 tracking the progress ofdownload requests for each participant, collaboration program 112 canutilize a threshold for determining whether to wait until a download ofthe requested file is complete for another participant or initialize anew download for the requesting participate. In an example, a firstparticipant of a collaboration session utilizes a mobile phone device todownload a file while traveling to the office on a subway, where theexternal connection is periodically cutting out. A second participant ofthe collaboration session utilizes a laptop computer device toinitialize a download of the file during the time that the firstparticipant is downloading the same file. Collaboration program 112 hasthe ability to determine, based on the download rate, to download thefile to the second participant rather than wait for the file to beavailable in a collaboration cache of the first participant.

In the event the file is not stored in cache (“no” branch, 206), themethod may query (208) an external device for the requested file. In theevent the file is stored in cache (“yes” branch, 206), the method maydetermine (216) if the file stored in cache meets guidelines.

The method may continue by querying (208) an external device for therequested file. In this embodiment, collaboration program 112 queries anexternal device via an external network (i.e., external network 110) toobtain the file requested by the participant of the collaborationsession. In one example, the external device is a storage system (i.e.,storage 118) located in a server computer 108 accessible bycollaboration program 112. In second example, the external device is astorage system located in a server computer accessible by the requestingparticipant, where the requesting participant has access to the servercomputer through an external network, such as, a data connection bycellular service provider. As previously mentioned, collaborationprogram 112 has the ability to query the external device for one or morefiles when a host participant joins a meeting. Collaboration program 112can query the external device for the one or more files once the hostparticipant joins the meetings rather than as a result of receivedrequests from other participants which may be for the one or more files.

The method may continue by receiving (210) the requested file from theexternal device. In this embodiment, collaboration program 112 receivesthe requested file from server computer 108 via external network 110.Collaboration program 112 can monitor a download rate for receiving therequested file from the external device (i.e., server computer 108) anddepending on the download rate, collaboration program 112 can determinewhether to wait for completion of the download prior to executing thesubsequent step or take another course of action. For example,collaboration program 112 can determine latencies in the download ratesof the requested files via external network 110 and can instruct theclient device of the requesting participant to initialize the downloadvia an external network independent of external network 110.Collaboration program 112 can also utilize a portion of file receivedthreshold, where the portion of file received threshold is a percentageof the file received from the external device. For example,collaboration program 112 utilizes a portion of file received thresholdof 80%, where once 80% of the file is received, collaboration program112 can initialize the sending of the received file to the requestingparticipant.

The method may continue by sending (212) the received file to therequesting participant. In this embodiment, collaboration program 112sends the received file to the requesting participant once the file iscompletely received from the external device (i.e., server computer108). In another embodiment, collaboration program 112 sends thereceived file to the requesting participant once a portion of filereceived threshold is met and as a result, collaboration program 112 canbegin sending the received file to the requesting participant prior tocompletely receiving the requested file. Collaboration program 112 alsohas the ability to send the received file to all participants of thecollaboration session in anticipation of receiving a request for thesame file. For example, if a host participant of a collaboration sessionis requesting a particular file not stored in collaboration cache 114,116A, 116B, and 116C, collaboration program 112 determines the otherparticipants of the collaboration session are to follow suit and sendsthe received file to all the participants of the collaboration session.In this example, client device 104A, 104B, and 104C can receive the filerequested by the host participant but not display the file. However, theclient device of the requesting host participant (i.e. the device thatrequested the file) displays the requested file.

The method may continue by storing (214) the received file in the cache.In this embodiment, collaboration program 112 stores the received filein a centralized collaboration cache (e.g., collaboration cache 114) andcan instruct the client device of the requesting participant to storethe received file in an associated collaboration cache as well (e.g.,collaboration cache 116A). Storing the received file in multiple cachesenables an alternative source for the file in the event the centralizedcollaboration cache becomes unavailable during the collaborationsession. For example, collaboration program 112 can store a firstportion of a received file in collaborative cache 116A in client device104A and second portion of the received file in collaborative cache116B.

Collaboration program 112 can store the received file for the durationof the collaboration session and subsequent to the completion of thecollaboration session, collaboration program 112 deletes the receivedfile from the collaboration cache. Alternatively, collaboration program112 can utilize a user defined duration for storing the received file.For example, collaboration program 112 can store the received file inthe centralized collaboration cache for 5 minutes and subsequent to 5minutes elapsing, collaboration program 112 can re-query the externaldevice for the received file. Utilizing the user defined duration forstoring the received file ensures that the file is the latest version.

The method may continue by determining (216) whether the file stored incache meets guidelines. A first example of a guideline includes aduration for which the file has been stored in the cache. Everyparticipant of a collaboration session can have a particular userdefined duration for storing a received file, where, for example, aduration defined by a first participant is different from a durationdefined by a second participant. For example, a file is being stored incollaboration cache 116A of a first participant's client device 104A fora duration of 5 minutes and currently the file has already been storedfor 4 minutes. A second participant with client device 104B isrequesting the file being stored in collaboration cache 116A andincludes a user defined duration of 3 minutes for storing receivedfiles. As a result, collaboration program 112 determines the file beingstored in collaboration cache 116A does not meet the guideline definedby the second participant with client device 104B. However, if the filebeing stored in collaboration cache 116A has only been stored for 1minute, collaboration program 112 determines the file meets theguideline defined by the second participant with client device 104B.

A second example of a guideline includes a type of device with acollaboration cache which stores the file. Every participant of acollaboration session can have a particular user defined list ofapproved device types from which a file can be received. The userdefined list of approved device types enables the participant to, forexample, avoid any additional formatting when transferring files betweentwo different types of devices, such as a mobile device utilizing afirst operating system and a laptop computer utilizing a secondoperating system. For example, a first participant of a collaborationsession stores the file in collaboration cache 116A of client device104A, where client device 104A is a mobile device. A second participantwhich sent the request for the file has a user defined list of approveddevice types that includes laptop computers and desktop computers.Collaboration program 112 determines the file does not meet theguideline since the file is being stored on a device not approved by thesecond participant. Additional guidelines include, but are not limitedto, the following: (i) file size guidelines, where only files above orbelow a certain size are permitted; (ii) security guidelines, where onlyfiles that meet certain security requirements are permitted; and/or(iii) network bandwidth guidelines, where the connection bandwidthbetween a requesting device and a storing device must be above or belowa certain amount.

In the event the file stored in cache does meet guidelines (“yes”branch, 216), the method may send the file to the requesting participant(218). In the event the file stored in cache does not meet guidelines(“no” branch, 216), the method may query (208) an external device forthe requested file. Subsequently, the method may perform steps 210through 214 as previously discussed to fulfill the request received fromthe participant.

The method may continue by sending (218) the file to the requestingparticipant. In this embodiment, collaboration program 112 sends thefile to the requesting participant from the collaboration cache on whichthe file is stored. In one example, a participant with client device104C requests a file and collaboration program 112 determines the fileis stored in collaboration cache 114 and meets the guidelines.Collaboration program 112 can send the file from collaboration cache 114to client device 104C, where the user can select whether or not storethe file in collaborative cache 116C on client device 104C. In anotherexample, a participant with client device 104C requests a file andcollaboration program 112 determines the file is stored in collaborationcache 116A on client device 104A. Collaboration program 112 can instructclient device 104A to send the file to client device 104C via internalnetwork 106. In yet another example, a participant with client device104C requests a file and collaboration program 112 determines the fileis stored in portions, where a first portion of the file is stored incollaboration cache 116A and a second portion of the file is stored incollaboration cache 116B. Collaboration program 112 can send the firstportion and the second portion of the file from collaboration cache 116Aand 116B, respectively, to client device 104C.

FIG. 3 depicts computer system 300, where server computer 102 is anexample of a system that includes collaboration program 112. Thecomputer system includes processors 301, cache 303, memory 302,persistent storage 305, communications unit 307, input/output (I/O)interface(s) 306 and communications fabric 304. Communications fabric304 provides communications between cache 303, memory 302, persistentstorage 305, communications unit 307, and input/output (I/O)interface(s) 306. Communications fabric 304 can be implemented with anyarchitecture designed for passing data and/or control informationbetween processors (such as microprocessors, communications and networkprocessors, etc.), system memory, peripheral devices, and any otherhardware components within a system. For example, communications fabric304 can be implemented with one or more buses or a crossbar switch.

Memory 302 and persistent storage 305 are computer readable storagemedia. In this embodiment, memory 302 includes random access memory(RAM). In general, memory 302 can include any suitable volatile ornon-volatile computer readable storage media. Cache 303 is a fast memorythat enhances the performance of processors 301 by holding recentlyaccessed data, and data near recently accessed data, from memory 302.

Program instructions and data used to practice embodiments of thepresent invention may be stored in persistent storage 305 and in memory302 for execution by one or more of the respective processors 301 viacache 303. In an embodiment, persistent storage 305 includes a magnetichard disk drive. Alternatively, or in addition to a magnetic hard diskdrive, persistent storage 305 can include a solid state hard drive, asemiconductor storage device, read-only memory (ROM), erasableprogrammable read-only memory (EPROM), flash memory, or any othercomputer readable storage media that is capable of storing programinstructions or digital information.

The media used by persistent storage 305 may also be removable. Forexample, a removable hard drive may be used for persistent storage 305.Other examples include optical and magnetic disks, thumb drives, andsmart cards that are inserted into a drive for transfer onto anothercomputer readable storage medium that is also part of persistent storage305.

Communications unit 307, in these examples, provides for communicationswith other data processing systems or devices. In these examples,communications unit 307 includes one or more network interface cards.Communications unit 307 may provide communications through the use ofeither or both physical and wireless communications links. Programinstructions and data used to practice embodiments of the presentinvention may be downloaded to persistent storage 305 throughcommunications unit 307.

I/O interface(s) 306 allows for input and output of data with otherdevices that may be connected to each computer system. For example, I/Ointerface 306 may provide a connection to external devices 308 such as akeyboard, keypad, a touch screen, and/or some other suitable inputdevice. External devices 308 can also include portable computer readablestorage media such as, for example, thumb drives, portable optical ormagnetic disks, and memory cards. Software and data used to practiceembodiments of the present invention can be stored on such portablecomputer readable storage media and can be loaded onto persistentstorage 305 via I/O interface(s) 306. I/O interface(s) 306 also connectto display 309.

Display 309 provides a mechanism to display data to a user and may be,for example, a computer monitor.

The programs described herein are identified based upon the applicationfor which they are implemented in a specific embodiment of theinvention. However, it should be appreciated that any particular programnomenclature herein is used merely for convenience, and thus theinvention should not be limited to use solely in any specificapplication identified and/or implied by such nomenclature.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

What is claimed is:
 1. A computer system comprising: one or morecomputer processors; one or more computer readable storage media; andprogram instructions stored on the computer readable storage media forexecution by at least one of the one or more computer processors, theprogram instructions comprising: program instructions to receive arequest from a first electronic device for a first file during acollaboration session between at least a first participant associatedwith the first electronic device and a second participant associatedwith a second electronic device; program instructions to determinewhether the first file is stored in one or more caches, wherein the oneor more caches are associated with one or more electronic devices in thecollaboration session; program instructions to, responsive todetermining the first file is stored in a first cache of the secondelectronic device, determine whether the first file stored in the firstcache of the second electronic device meets a set of guidelines; programinstructions to, responsive to determining the first file stored in thefirst cache of the second electronic device meets the set of guidelines,wherein the set of guidelines includes at least a duration of time thefirst file has been stored in the cache of the second electronic deviceand a type of device for the second electronic device, send the firstfile from the first cache of the second electronic device via aninternal network to the first electronic device; program instructions toreceive a request for a second file from the first electronic device;program instructions to determine whether the second file is stored inthe one or more caches; program instructions to, responsive todetermining the second file is not stored in the one or more caches,query an external electronic device through an external network for thesecond file; and program instructions to, responsive to receiving thesecond file from the electronic external device, store a first portionof the second file in a second cache of the first electronic device andstoring, by one or more processors, a second portion of the second filein the first cache of the second electronic device.